JP2015161747A - Sheet processing device, image forming system, and control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the work load of a user when a failure occurs.SOLUTION: A sheet processing device to be mounted on an image forming apparatus includes: processing means for processing a sheet; conveyance means which conveys a sheet discharged from the image forming apparatus; and control means which controls the processing means and the conveyance means. When the processing means is determined to have entered an abnormal condition during processing a sheet, the control means controls the conveyance means to stop conveying the sheet, and the processing means to execute recovery operation. After the recovery operation, the conveyance means restarts conveying the sheet.

Description

  The present invention relates to a sheet processing apparatus, an image forming system, and a control method.

  An image forming apparatus that forms an image on a sheet, such as a copying machine, a printer, a facsimile machine, or a multifunction machine thereof, may include a sheet processing apparatus on the sheet discharge side. As a sheet processing apparatus, for example, there is a sheet processing apparatus that performs stacking processing on a sheet with a stapler after the sheets discharged from the image forming apparatus are stacked and aligned on a processing tray.

  By the way, in the stapler, the binding needle may not be normally ejected from the stapler, that is, a staple jam may occur. In view of this, a sheet processing apparatus has been proposed in which a needle jam is notified to a user when a needle jam is detected (for example, Patent Document 1). Further, a sheet processing apparatus has been proposed in which, when an abnormality such as an overload is detected in the upstream stapler, the downstream sheet processing operation is stopped (for example, Patent Document 2). In these sheet processing apparatuses, when it is detected that an abnormality such as a staple jam has occurred in the stapler, the operation is stopped, and the user can be prompted to perform the jam processing.

JP-A-11-322174 JP 2007-261700 A

  When an abnormality such as a staple jam occurs, the sheet may remain in the conveyance path of the sheet processing apparatus. In order to restore the apparatus, the user may have to perform an operation of removing the remaining sheet from the conveyance path.

  An object of the present invention is to reduce a user's work burden when an abnormality occurs.

  According to the present invention, for example, a sheet processing apparatus that can be attached to an image forming apparatus, a processing unit that processes a sheet, a transport unit that transports a sheet discharged from the image forming apparatus, A processing unit and a control unit that controls the conveying unit, and the control unit causes the conveying unit to stop conveying the sheet when the processing unit determines that an abnormal state has been reached during processing of the sheet. There is provided a sheet processing apparatus that causes the processing means to perform a return operation, and after the return operation, causes the transport means to resume transport of the sheet.

  According to the present invention, it is possible to reduce the work burden on the user when an abnormality occurs.

1 is an explanatory diagram of an image forming system according to an embodiment of the present invention. Explanatory drawing of the sheet processing apparatus which concerns on one Embodiment of this invention. The disassembled perspective view of a processing tray. Explanatory drawing of a stapler. The block diagram of a control part. The flowchart which shows the example of control. The flowchart which shows the example of control. The flowchart which shows the example of control. The flowchart which shows the example of control. The flowchart which shows the example of control. The figure which shows the example of the time difference between sheet bundles. The figure which shows the example of information.

  Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings. In addition, the numerical value shown in this Embodiment is a reference numerical value for making this Embodiment easy to understand, and is not a numerical value which limits this invention.

[First Embodiment]
FIG. 1 is an explanatory diagram of an image forming system A according to an embodiment of the present invention. The image forming system A constitutes an electrophotographic copying machine, and includes an image forming apparatus 100 and a sheet processing apparatus 119 functioning as a finisher. FIG. 1 shows a cross-sectional structure of the image forming apparatus 100 along the sheet conveyance direction.

(Image forming device)
The image forming apparatus 100 includes an image forming apparatus main body 100 </ b> A and a document feeding apparatus 102 and an image reading unit 101. The image forming apparatus main body 100A includes an image forming unit 100B, a paper feeding unit 100C, and the like.

  The document feeder 102 is a device that transports the document D to the reading position 108. When an image of the document D placed on the document placement unit 103 is read by the user (in the case of so-called flow reading), first, the document D is sequentially separated one by one by the feeding unit 104. Thereafter, the toner is supplied to the registration roller pair 105. Next, the document D is temporarily stopped by the registration roller pair 105, a loop is formed, and skew is corrected. Thereafter, the document D passes through the introduction path 106 and passes through the reading position 108, whereby the image of the document is read. The document D that has passed the reading position 108 passes through a discharge path 107 and is discharged onto a discharge tray 109 by a discharge roller 110.

  On the other hand, the image reading unit 101 that reads an original image irradiates the light of the illumination system 111 to the original D that passes through the reading position 108, and the reflected light reflected from the original D is reflected by the mirror 112 to the optical element 113 (for example, CCD or other). Element). As a result, the image reading unit 101 obtains image data corresponding to the document image and sends the image data to the image forming unit 100B.

  The image forming unit 100B forms an image on a sheet such as paper. The image forming unit 100B first forms a latent image by irradiating the photosensitive drum 114 with laser light based on image data by an exposure unit (not shown).

  Next, the latent image formed on the photosensitive drum 114 is developed with toner supplied from a toner supply device (not shown) to form a toner image. In parallel with such a toner image forming operation, the sheets S stored in the cassette 115 of the paper feeding unit 100C are separated one by one and sent to the image forming unit 100B. The sheet S enters between the photosensitive drum 114 and the transfer device 116 with a timing by the registration roller pair 151.

  Then, the toner image on the photosensitive drum 114 is transferred to the sheet S by the transfer device 116. Thereafter, the sheet S to which the toner image is transferred is heated and pressed while passing through the fixing device 117, the toner image is fixed, and is discharged to the sheet processing apparatus 119 by the discharge roller pair 120. When an image is formed on the back side of the sheet, the sheet S is reversed by the re-conveying unit 118 and then conveyed between the photosensitive drum 114 and the transfer device 116. The sheet S on which images are formed on both sides is then discharged to the sheet processing apparatus 119.

  These processes are executed under the control of the control unit 201 provided in the image forming apparatus 100. The control unit 201 includes, for example, a storage unit such as a ROM and a RAM, a CPU that executes a program stored in the storage unit, an interface unit, and the like. The interface unit includes a communication interface for communicating data with the sheet processing apparatus 119 in addition to an interface for inputting / outputting signals to / from actuators and sensors provided in the image forming apparatus 100.

(Sheet processing equipment)
FIG. 2 is an explanatory diagram of the sheet processing apparatus 119 and is a schematic cross-sectional view along the sheet conveying direction. FIG. 3 is an exploded perspective view of the processing tray. The sheet processing apparatus 119 will be described with reference to FIGS.

  The sheet processing apparatus 119 is detachably attached to the apparatus main body 100A of the image forming apparatus 100, and performs a predetermined process on the sheet discharged from the apparatus main body 100A. Examples of the process for the sheet include a punching process for punching a sheet in order, a sorting process for sequentially taking a plurality of sheets and aligning them into a bundle, and a non-sorting process. Examples of the process for the sheet include a staple process for binding the bundled sheet bundle with a stapler, and a bookbinding process for binding and folding the sheet bundle.

  As a sheet processing mechanism for enabling such processing, the sheet processing apparatus 119 includes a stapler 132, a punch unit 119A, a bookbinding unit 139, and the like. The stapler 132 and the bookbinding unit 139 are provided in the sheet processing apparatus main body 119B.

  The sheet processing apparatus main body 119B includes a sheet conveyance mechanism that conveys a sheet discharged from the apparatus main body 100A and passed through the punch unit 119A. The sheet conveying mechanism includes a common conveying roller pair 137, an entrance roller pair 121, an intermediate discharge roller pair 126, a bundle discharge roller pair 127, and the like. When focusing on the stapler 132, the common conveyance roller pair 137, the entrance roller pair 121, and the intermediate discharge roller pair 126 are conveyance units that convey the sheet to the stapler 132. The bundle discharge roller pair 127 is a conveyance unit that discharges the sheets processed by the stapler 132 to the stacking tray 128.

  A path switching member 122 that switches the transport path is provided downstream of the common transport roller pair 137. The path switching member 122 is operated by a drive source (not shown) such as a solenoid, and guides the sheet to the processing tray 150 side in the non-sort mode, the sort mode, and the staple mode. In the bookbinding mode, the sheet is guided to the bookbinding unit 139 side.

  The sheet guided to the processing tray 150 side by the path switching member 122 is discharged onto the processing tray 150 by the inlet roller pair 121 and the intermediate discharge roller pair 126. At this time, the sheet is once conveyed downstream by a predetermined amount of forward rotation of the bundle discharge roller pair 127, and then conveyed upstream by reverse rotation, and the rear end contacts the rear end stoppers 130b and 130c (FIG. 3). And the rear end is aligned. When a sheet is stacked on the processing tray 150, the upper roller 127a of the bundle discharge roller pair 127 (FIG. 3) rises away from the lower roller 127b and receives the sheet between the lower roller 127b.

  Thereafter, the upper roller 127a descends and sandwiches the sheet with the lower roller 127b to rotate forward and reversely rotate. The upper roller 127 a performs this operation every time the sheet is discharged to the processing tray 150. The common conveyance roller pair 137, the entrance roller pair 121, and the intermediate discharge roller pair 126 are rotated by the conveyance motor 210. The bundle discharge roller pair 127 is rotated by a bundle discharge motor 211. Further, the upper roller 127a is moved in the vertical direction by the rotation of the swing motor 212 via a rotational force transmission mechanism (not shown).

  Then, the sheets are width aligned by the width alignment plates 129a and 129b (FIG. 3). The front width alignment plate 129a is moved in the width direction of the sheet by the rotation of the front alignment motor 213 via a rotational force transmission mechanism (not shown). The depth alignment plate 129b is also moved in the sheet width direction by the rotation of the depth alignment motor 214 via a rotational force transmission mechanism (not shown).

  The sheets stacked in a bundle on the processing tray 150 are stapled by the stapler 132 as necessary, and the bundle discharge roller pair 127 rotates and the trailing end stopper 130a (FIG. 3) moves in the arrow X direction. And are discharged to the stacking tray 128. The rear end stopper 130a is moved in the arrow X direction by rotation of the rear end assist motor 215 via a torque transmission mechanism (not shown). The stapling process by the stapler 132 will be described later.

  Note that the sheet processing apparatus main body 119B can process sheets that have been punched by the punch unit 119A in the non-sort mode, the sort mode, and the staple mode, respectively.

  On the other hand, the bookbinding unit 139 is a unit that performs bookbinding, and includes two bookbinding staplers 138 arranged in the sheet width direction, a folding unit 140 that folds a sheet bundle, and the like.

  The sheet guided to the bookbinding unit 139 by the path switching member 122 is conveyed to the bookbinding unit 139 through the booklet entrance roller pair 134. Then, the bookbinding unit 139 binds the center of the sheet bundle with the bookbinding stapler 138, bends the center portion of the bundle with the folding unit 140 to form the sheet bundle into a booklet, and then discharges the sheet bundle to the bookbinding tray 141. This completes the bookbinding process.

(Stapler)
Next, a series of stapling processes performed by the stapler 132 will be described in detail. FIG. 4 is a schematic sectional view of the stapler 132.

  The stapler 132 is waiting in advance at a desired clinch position for the sheet bundle according to the staple mode. The stapler 132 staples the sheet bundle at the time when the discharge and alignment of the final sheet of the bundle are completed.

  Here, the configuration of the stapler 132 will be described. As shown in FIG. 4, the stapler 132 includes a movable upper jaw 132 a and a fixed lower jaw 132 b. The stapler 132 is bound by binding a sheet bundle between the upper jaw portion 132a and the lower jaw portion 132b.

  The upper jaw part 132a constitutes an operating part that can be displaced between an upper standby position positioned before the stapling process and a lower operating position positioned during the stapling process. When the upper jaw part 132a is lowered to the operating position and the sheet bundle is clinched together with the lower jaw part 132b, the needle protruding from the lower jaw part 132b penetrates the sheet bundle. Then, the end of the needle is bent inward by the upper jaw 132a, and the sheet bundle is stapled so that the sheet bundle is held by the needle.

  After the clinching is completed, the upper jaw part 132a rises again to the standby position, and prepares for the next clinching operation in a state in which a predetermined distance from the lower jaw part 132b is maintained. As a result, the stapling process ends.

  The upper jaw 132a is lowered by rotating (forward rotation) the stapler motor 216 in the direction of arrow a via a cam mechanism (not shown). Further, after the clinch is completed, the upper jaw 132a is raised again by further rotating (forward rotation) in the direction of the arrow a.

  By the way, in the stapler 132, as an example in which the staple is not normally ejected, that is, the stapler 132 is in an abnormal state during the processing on the sheet, the occurrence of a staple jam is cited. In the case of this embodiment, the presence or absence of occurrence of this abnormal state is provided with a sensor for detecting the operation, and the presence or absence of occurrence of the abnormal state is determined based on the detection result.

  Specifically, in the present embodiment, a stapler HP sensor 221 is provided in the stapler 132. The sensor 221 detects that the upper jaw 132a is at the standby position (FIG. 4A) that is the home position. The rotation time of the stapler motor 216 is measured after the sensor 221 detects that the upper jaw 132a is located at the standby position. Specifically, the time until the upper jaw 132a returns to the standby position (FIG. 4 (a)) after the clinching end from the start of forward rotation of the stapler motor 216 (FIG. 4 (b)) is counted. When returning to the standby position within a predetermined time, it is determined that the operation is normally completed.

  However, when a needle jam or the like occurs, the needle protruding from the lower jaw portion 132b cannot penetrate the sheet bundle, and is jammed and cannot be ejected normally. Therefore, the load on the stapler motor 216 increases, the motor lock is generated, the rotation is slowed, and the upper jaw portion 132a cannot return to the standby position within a predetermined time. At this time, it is determined that a needle jam has occurred, and it is determined that there is an abnormality.

  As another example of the sensor for detecting the operation, for example, the current value of the stapler motor 216 may be measured to determine the occurrence of an abnormal state (needle jam) due to overload. Further, a penetration detection sensor that detects that the needle has penetrated the sheet bundle may be used to detect that the needle has not penetrated the sheet bundle and determine the occurrence of an abnormal state (needle jam).

  When the staple jam occurs, the stapler 132 stops in a state where the upper bundle portion 132a and the lower jaw portion 132b sandwich the sheet bundle and is bound (FIG. 4B). At this time, the return operation of the stapler 132 is performed in order to discharge the sheet bundle from the processing tray 150 to the stacking tray 128. The return operation of the present embodiment is an operation of raising the upper jaw 132a and returning it to the standby position. In the present embodiment, this is realized by rotating (reversing) the stapler motor 216 in the direction of the arrow b. If it can be confirmed from the detection result of the stapler HP sensor 221 that the upper jaw 132a has returned to the standby position, it is determined that the return has succeeded. If it cannot be confirmed that the upper jaw 132a has returned to the standby position even when the stapler motor 216 is reversely rotated for a predetermined time, it is determined that the return has failed due to a failure of the stapler 132.

  FIG. 5 is a block diagram of the control unit 200 of the sheet processing apparatus 119. In FIG. 5, a solid line extending from each block toward the control unit 200 indicates that each block and the control unit 200 are connected so that signals can be exchanged.

  The control unit 200 includes a CPU 202, a ROM 203 that stores programs and various data, a RAM 204 that is temporarily used for data storage, and the like. Then, the CPU 202 executes processing shown in each flowchart described later based on the program. The control unit 200 exchanges control signals, sensor signals, and the like with the control unit 201 of the image forming apparatus via the communication unit 225.

  Note that one of the control unit 200 of the sheet processing apparatus and the control unit 201 of the image forming apparatus 100 may be incorporated in the other. For example, a configuration in which the control unit 201 also controls the sheet processing apparatus 119 can be employed.

  The control unit 200 is connected to a transport motor 210, a bundle discharge motor 211, a swing motor 212, a front alignment motor 213, a back alignment motor 214, a rear end assist motor 215, a stapler motor 216, and the like. In addition, an inlet path sensor 220, a stapler HP sensor 221, various HP sensors 222, a time measuring unit 223, a counting unit 224, a communication unit 225, and the like are connected to the control unit 200.

  The time measurement unit 223 is a counter, for example, and measures the rotation time of the stapler motor 216 and uses it to determine the occurrence of the abnormal state described above. The communication unit 225 can receive information on the surface property, basis weight, and the like of the sheet from the control unit 201 of the image forming apparatus, and the control unit 200 can determine the type of the sheet. The counting unit 224 counts the number of sheet bundles to be stapled by counting a pre-region signal described later.

  Next, a control example executed by the CPU 202 of the control unit 200 will be described. FIG. 6 is a flowchart for explaining the stapling process.

  The CPU 202 aligns the sheets by rear end alignment that abuts the rear end of the sheet on the processing tray 150 against the rear end stoppers 130a, 130b, and 130c, and width alignment of the sheet bundle by the front alignment plate 129a and the back alignment plate 129b. Processing is performed (S601). Next, the CPU 202 causes the stapler 132 to perform a needle binding operation described later (S700). Details will be described later.

  Subsequently, the CPU 202 determines whether or not the stapler 132 has reached an abnormal state (here, staple jam) by this staple binding operation (S603). If the CPU 202 determines that a staple jam has occurred (YES in S603), the CPU 202 stops the conveyance motor 210 (S604) so that the subsequent sheet does not enter the processing tray 150. Further, the controller 201 of the image forming apparatus 100 is instructed to temporarily stop the sheet conveyance (S605). This prevents a new sheet from being conveyed from the image forming apparatus 100 to the sheet processing apparatus.

  Note that in the image forming apparatus 100, there is a case where the sheet cannot be temporarily stopped on the conveyance path from the registration roller pair 151 through the fixing device 117. Therefore, when the control unit 201 of the image forming apparatus 100 determines that there is a possibility that the sheet is temporarily stopped on the conveyance path, the control unit 201 stores the preceding sheet with respect to the CPU 202 in a buffer unit (not illustrated). An instruction may be given and the sheet may be temporarily stopped when the sheet passes through the fixing device 117. The buffer unit is a place that is arranged on the upstream side of the processing tray 150 and temporarily stores the image-formed sheet and waits until the processing of the preceding sheet is completed.

  Thereafter, the CPU 202 causes the stapler 132 to perform a return operation described later (S800). Here, the CPU 202 determines whether or not the return of the stapler 132 has succeeded in this return operation (S607). If it is determined that the return is successful (YES in S607), the CPU 202 drives the rear end assist motor 215 and the bundle discharge motor 211 to discharge the bundle of sheets on the processing tray 150 (S608).

  The CPU 202 redrives the transport motor 210 that has been stopped (S609). Further, the control unit 201 of the image forming apparatus 100 is instructed to resume the conveyance of the sheet (S610), and this process is terminated. Thus, after the returning operation, the sheet conveyance is resumed, and the image forming apparatus 100 is instructed to resume the sheet conveyance.

  As a result, the sheets remaining in the image forming apparatus 100 and the sheet processing apparatus 119 can be discharged to the stacking tray 128, and the user need not perform the sheet removal operation. Therefore, it is possible to reduce the work burden on the user when an abnormality occurs.

  Note that the sheet conveyed after the return of the staple jam may be sorted into a position different from the sheet that has been normally stapled. In that case, the sheet bundle can be shifted by the front alignment plate 129a and the back alignment plate 129b.

  Next, in S603, when it is determined that a staple jam has not occurred (NO in S603), the CPU 202 activates the rear end assist motor 215 and the bundle discharge motor 211 in order to discharge the bundle of sheets on the processing tray 150. Driven (S608), the process is terminated.

  If the return fails in S607 (NO in S607), the CPU 202 determines that the stapler 132 has failed, stops the apparatus, and notifies the controller 201 of the image forming apparatus 100 of an error (S608). The process ends.

  Next, the subroutine of S700 will be described based on FIG. FIG. 7 is a flowchart for explaining the stapler staple binding operation.

  The CPU 202 starts time measurement by the time measurement unit 223 (S701), and causes the stapler motor 216 to rotate forward (S702). Thus, the stapler 132 holds the sheet bundle between the upper jaw portion 132a and the lower jaw portion 132b and binds them. Then, the CPU 202 determines from the output of the stapler HP sensor 221 whether or not the upper jaw 132a has moved up and returned to the standby position after the clinching is finished (S703). If it has not returned to the standby position (NO in S703), the CPU 202 determines whether or not a predetermined time (400 ms as an example here) has elapsed from the time measurement unit 223 from the start of forward rotation of the stapler motor 216 (S706). Here, 400 ms is assumed to be the maximum time in the staple processing specifications of the stapler 132. If 400 ms has elapsed (YES in S706), the CPU 202 determines that a staple jam has occurred (S707). The CPU 202 brakes and stops the stapler motor 216 (S704), ends the time measurement unit 223 (S705), and ends this process.

  If the CPU 202 detects that the upper jaw 132a of the stapler 132 is again raised and returned to the standby position within 400 ms in S706 (YES in S703), the CPU 202 determines that the stapling process has ended normally. . Then, the stapler motor 216 is braked and stopped (S704), the time measurement by the time measuring unit 223 is ended (S705), and the present process is terminated.

  Next, the subroutine of the process S800 will be described based on FIG. FIG. 8 is a flowchart for explaining the stapler return operation.

  The CPU 202 starts time measurement by the time measurement unit 223 (S801), and reverses the stapler motor 216 (S802). As a result, the stapler 132 can return from the state where the upper bundle portion 132a and the lower jaw portion 132b have pinched the sheet bundle and bound and stopped. Then, the CPU 202 determines whether or not the upper jaw 132a has moved up and returned to the standby position from the detection result of the stapler HP sensor 221 (S803).

  If the upper jaw portion 132a has not returned to the standby position (NO in S803), the CPU 202 determines whether or not a predetermined time (400 ms as described above) has elapsed since the time measurement unit 223 started normal rotation of the stapler motor 216. Judgment is made (S807). If 400 ms has elapsed (YES in S807), the CPU 202 determines that the recovery has failed (S808). The CPU 202 applies a brake to the stapler motor 216 to stop it (S805), ends the time measurement by the time measuring unit 223 (S806), and ends this process.

  If the CPU 202 detects that the upper jaw 132a of the stapler 132 has returned to the standby position within 400 ms (NO in S807) in the process S807 (YES in S803), the CPU 202 determines that the return has succeeded (S804). Then, the stapler motor 216 is braked to be stopped (S805), the time measurement by the time measuring unit 223 is ended (S806), and this process is ended.

  As described above, according to the present embodiment, after the staple jam is detected, the stapler performs the return operation and discharges the sheet to the outside of the apparatus, so that the user does not need to perform the sheet removal operation, and the operation is performed correspondingly. The rate can be increased.

[Second Embodiment]
In the first embodiment described above, the image forming apparatus 100 is instructed to temporarily stop sheet conveyance so that the subsequent sheet is not conveyed into the sheet processing apparatus 119 after the occurrence of a staple jam. Thereafter, the stapler 132 is returned to discharge the sheet bundle on the processing tray 150, and then the conveyance of the sheet is resumed.

  In the present embodiment, an instruction regarding the sheet discharge interval is given to the image forming apparatus 100 based on information regarding the sheet to be processed. That is, it is estimated whether or not an abnormal condition is likely to occur based on the information regarding the sheet to be processed.

  More specifically, it is determined beforehand based on a pre-region signal whether or not a staple jam may occur during stapling processing of a sheet bundle, and when it is determined that there is a possibility of a staple jam, the image forming apparatus 100 is informed. And instructing that the conveyance interval between the sheet bundle to be stapled and the succeeding sheet is increased by a predetermined time. As a result, even if a staple jam occurs, it is difficult for a remaining sheet to exist in the image forming apparatus 100 and the sheet processing apparatus 119, so that the user does not have to perform a sheet removal operation. In other words, the burden on the user is reduced by preventing the user from performing a sheet removal operation.

  Note that the processing of this embodiment can be combined with the processing of the first embodiment.

  Specific examples will be described below. FIG. 11 is a diagram illustrating an example of the time required for the stapling process. When the preceding bundle is stapled, when discharging the subsequent bundle of sheets from the image forming apparatus 100, it is necessary to set a discharge interval for the preceding bundle for a predetermined time. When it is determined that there is a possibility of needle jam, the discharge interval is made longer than when it is determined that there is no possibility. FIG. 11A assumes that there is no possibility of occurrence of needle jam in the preceding bundle, and FIG. 11B assumes that possibility of occurrence of needle jam in the preceding bundle. Is.

  If there is no possibility of the occurrence of a needle jam, as illustrated in FIG. 11 (A), an interval of 900 ms is set as the time from passing the leading edge of the last sheet of the preceding bundle to passing the leading edge of the first sheet of the succeeding bundle. Open. The breakdown includes 400 ms as a staple binding factor (staple processing time). This assumes the maximum stapling time according to the stapler specification described above. Further, 500 ms is counted as a bundle discharge factor (time for discharging the sheet bundle to the stacking tray 128). As a result, the total is 900 ms.

  On the other hand, if there is a possibility that a needle jam will occur, an interval of 1500 ms is set as the time from the passage of the leading end of the last sheet of the preceding bundle to the passage of the leading end of the first sheet of the succeeding bundle. The breakdown requires 400 ms for the staple binding factor, 500 ms for the bundle discharge factor, and 600 ms for the return factor. The return factor is the time required for the return operation, which is a numerical value obtained by adding the wait time 200 ms for switching between normal rotation and reverse rotation of the stapler motor 216 to the above-described maximum return time according to the stapler specifications. In this way, at least the time required for the return operation is added.

  Next, four main signals exchanged between the apparatus main body 100A of the image forming apparatus and the sheet processing apparatus 119 will be described with reference to FIG. Four signals are fed from one sheet feeding unit 100C of the image forming apparatus 100 to the sheet processing apparatus 119, and the sheet bundle is discharged from the bundle discharge roller pair 127. This is a signal that is transmitted and received in order in the interval up to.

(Pre-Region signal)
The pre-region signal includes information regarding the sheet to be processed. The pre-region signal is, for example, sheet information, operation mode information such as stapling and punching, stacking position information such as a discharge tray, and the like. The pre-region signal is transmitted from the control unit 201 of the apparatus main body 100A of the image forming apparatus 100 to the control unit 200 of the sheet processing apparatus 119 at the paper feeding timing of the image forming apparatus 100. The control unit 200 of the sheet processing apparatus returns a sheet processing time based on the pre-region signal to the control unit 201.

  The sheet processing time is a time required for the sheet processing apparatus 119 to process a sheet (sheet alignment processing, stapling processing, etc.). In other words, the sheet processing time is a time for regulating the corresponding sheet (the sheet discharged by the image forming apparatus 100) so as not to be earlier than the timing at which the sheet processing apparatus 119 can receive. Specifically, the sheet processing apparatus 119 becomes ready to receive a sheet from the transfer timing when the previous sheet is transferred from the image forming apparatus 100 to the sheet processing apparatus 119, and corresponds to the sheet processing apparatus 119 from the image forming apparatus 100. This is the time until the delivery timing when the sheet is delivered.

(Region signal)
This is a timing signal that is notified to the transfer unit 116 and the like when the registration roller pair 151 of the image forming apparatus 100 restarts from the temporary stop of the sheet.

(Discharge signal)
This timing signal is notified from the control unit 201 of the image forming apparatus to the control unit 200 of the sheet processing apparatus immediately before delivering the sheet from the image forming apparatus 100 to the sheet processing apparatus 119. The interval from the notification of the previous sheet to the notification of the corresponding sheet must not be shorter than the previously described sheet processing time.

(Sorter discharge signal)
This is a timing signal notified from the control unit 200 of the sheet processing apparatus to the control unit 201 of the image forming apparatus at the timing when the sheet bundle is discharged from the bundle discharge roller pair 127 of the sheet processing apparatus 119.

  The above four signals are only the timing of signals for one sheet or sheet bundle, and actually a plurality of sheets are processed in parallel. Which sheet is a signal can be managed even if a plurality of sheets are processed in parallel by giving an ID and notifying it.

  Next, the stapling process of the second embodiment will be described based on the flowcharts of FIGS.

  FIG. 9 is a flowchart for explaining the stapling process of the sheet processing apparatus according to the second embodiment.

  The CPU 202 performs processing based on the pre-region signal (pre-region processing described later) (S1000). Next, the CPU 202 performs rear end alignment that abuts the rear end of the sheet on the processing tray 150 against the rear end stoppers 130a, 130b, and 130c, and width alignment of the sheet bundle by the front alignment plate 129a and the back alignment plate 129b. Sheet alignment processing is performed (S902). The CPU 202 determines whether or not the sheet is the final sheet in the bundle (S903). If the sheet is not the final sheet in the bundle, that is, if it is not the end of the bundle (NO in S903), the process returns to S1000. Every time a sheet is conveyed, S1000, S902, and S903 are repeated.

  If it is the last sheet in the bundle in S903, that is, if the end of the bundle (YES in S903), the CPU 202 moves the stapler 132 to a desired clinch position with respect to the sheet bundle and causes the stapler to perform a staple binding operation (S700). . Here, the CPU 202 determines whether or not a staple jam has occurred in the stapler staple binding operation (S905).

  If the CPU 202 determines that a staple jam has occurred (YES in S905), the CPU 202 causes the stapler 132 to perform a return operation (S800). Here, since the conveyance interval of the succeeding sheet is opened in advance in S1000, the returning operation can be performed in a state where the sheet does not remain in the apparatus.

  Then, the CPU 202 determines whether or not the return of the stapler 132 has succeeded in this return operation (S907). When it is determined that the return is successful (YES in S907), the CPU 202 drives the rear end assist motor 215 and the bundle discharge motor 211 to discharge the bundle of sheets on the processing tray 150 (S908), and performs this processing. Exit. As a result, even if a staple jam occurs, it is possible to continuously process subsequent sheets. That is, even if a staple jam occurs, there is no remaining sheet in the image forming apparatus 100 and the sheet processing apparatus 119, so that the user does not have to perform a sheet removal operation.

  In S905, when it is determined that the staple jam has not occurred (NO in S905), the CPU 202 drives the rear end assist motor 215 and the bundle discharge motor 211 to discharge the bundle of sheets on the processing tray 150. (S910), this process ends. Thereafter, if needle jam does not occur continuously, it may be determined in S1000 that there is no possibility of needle jam occurrence, and the conveyance interval may not be opened unnecessarily.

  If the return fails in step S907 (NO in step S907), the CPU 202 determines that the stapler 132 has failed, stops the apparatus, and notifies the controller 201 of the image forming apparatus of an error (S909). The process ends.

  In this processing, the subroutines of processing S700 and processing S800 are the same as the contents described in the first embodiment, and thus description thereof is omitted.

  Next, the subroutine of S1000 will be described based on FIG. FIG. 10 is a flowchart for explaining the pre-region process.

  Based on the pre-region signal, the CPU 202 acquires information about the sheet such as the sheet size, the sheet type, the sheet basis weight, and the number of sheet bundle binding locations (S1001). The CPU 202 counts the number of sheet bundles to be stapled by the counting unit 224 using the number of pre-region signals (S1002). The CPU 202 determines from the sheet information of the acquired pre-region signal whether it is the first sheet in the bundle (S1003). If it is not the first sheet in the bundle (NO in S1003), there is no need to increase the sheet discharge interval. Therefore, the required processing time is set to 0 in S1008, and this processing is terminated. Supplementally, this is the sheet conveyance interval between the second sheet, the third sheet, the fifth sheet, and the sixth sheet in FIGS. 11A and 11B and the preceding sheet. Note that the first sheet of the first bundle is the top sheet, but since it is the top of the job and there is no preceding sheet, the sheet conveyance interval need not be opened.

  In the case of the first sheet in the bundle in S1003 (YES in S1003), the sheet preceding this sheet is the last sheet in the sheet bundle to be stapled, so it is necessary to increase the sheet conveyance interval. The CPU 202 refers to the staple jam determination table (S1004), and determines whether or not there is a possibility of occurrence of staple jam in the staple processing of the preceding sheet (S1005).

  Here, FIG. 12 shows a needle jam determination table. The needle jam determination table is an example of information that associates information about a sheet to be processed with whether or not there is a possibility of an abnormal state during processing on the sheet.

  The example of FIG. 12 shows the relationship between the number of sheet bundles to be stapled and the possibility of needle jam occurrence for each sheet type. The possibility of needle jams is determined experimentally or empirically. As a tendency, the greater the number of sheet bundles, the more likely needle jams occur. Also, the harder the sheet, the more likely it is that needle jam will occur. As for the hardness, it is assumed that plain paper is the softest and cardboard 2 is the hardest.

  Here, since the presence or absence of occurrence of needle jam is targeted, the number of sheet bundles and the type of sheet are referred to. However, if the target abnormal state is different, information regarding the sheet may refer to different information. However, in any case, it is considered that at least the sheet type is often referred to.

  The table in FIG. 12 is stored in the ROM 203. Further, the needle jam determination table may refer to a past needle jam history. In this case, the table is stored in the RAM 204 or a nonvolatile memory (not shown).

  If the CPU 202 determines that there is a possibility of occurrence of a staple jam in the preceding sheet in S1005 (YES in S1005), the interval between sheets fed into the processing tray 150 corresponds to 1500 ms as shown in FIG. An instruction is issued to the image forming apparatus 100 so as to leave the sheet conveyance distance (S1006), and this process is terminated.

  If the CPU 202 determines in step S1005 that there is no possibility of occurrence of a staple jam in the preceding sheet (NO in step S1005), the interval between sheets fed into the processing tray 150 corresponds to 900 ms as shown in FIG. An instruction is issued to the image forming apparatus 100 so as to leave as much as the sheet conveyance distance to be performed (S1006), and this processing is terminated.

  As described above, the possibility of the staple jam of the preceding sheet is judged by the pre-region process, and the sheet conveyance interval is increased by a predetermined time, so that even when the staple jam occurs in the preceding sheet, the process for the return operation is performed. Since the time is secured in advance, the return operation can be executed by the stapler 132. Furthermore, if the return is successful, the sheet on the processing tray can be discharged and the subsequent sheet processing can be continued. Therefore, after the staple jam is detected, the stapler performs a return operation and discharges the sheet to the outside of the apparatus. Therefore, the user does not have to perform the sheet removing operation, and the operating rate can be increased correspondingly.

[Other Embodiments]
In the above-described embodiment, the embodiment of the present invention has been described with respect to the abnormal state of the stapler 132. However, the present invention is not limited to this, and the abnormal state of various processing mechanisms can be targeted. . For example, the bookbinding stapler 138 may be used.

  In the above-described embodiment, the staple binding process using the metal binding needle as the binding member has been described. However, for example, a so-called “needle” is formed in which a sheet bundle is bound by using a paper tape piece as a binding member by forming a cut in the sheet bundle. No staples ", and the same effect can be obtained by applying the present invention to the sheet processing apparatus.

  In the above-described embodiment, the staple jam of the stapler 132 is illustrated as an example of the abnormal state, but the present invention is not limited to this. For example, punch punching jam of the punch unit 119A, saddle jam of the bookbinding unit 140, and the like can be applied.

  The present invention can also be realized by executing the following processing. That is, software (program) that realizes the functions of the above-described embodiments is supplied to a system or apparatus via a network or various storage media, and the computer (or CPU, MPU, etc.) of the system or apparatus executes the program. It is a process to read and execute.

A Image forming system 100 Image forming apparatus 119 Sheet processing apparatus

Claims (15)

A sheet processing apparatus that can be attached to an image forming apparatus,
Processing means for processing the sheet;
Conveying means for conveying a sheet discharged from the image forming apparatus;
Control means for controlling the processing means and the conveying means,
The control means includes
When it is determined that the processing unit has reached an abnormal state during processing of the sheet, the conveyance unit stops conveyance of the sheet, causes the processing unit to perform a return operation, and after the return operation, the conveyance unit causes the sheet to Resume transport,
A sheet processing apparatus. The sheet processing apparatus according to claim 1,
The control means includes
When the processing unit determines that an abnormal state has been reached during processing of the sheet, the image forming apparatus is instructed to stop discharging the sheet, and after the return operation, the image forming apparatus is Instructing the resumption of discharge,
A sheet processing apparatus. The sheet processing apparatus according to claim 1 or 2,
The conveying means is
A first conveying unit that conveys the sheet to the processing means;
A second transport unit that discharges the sheet processed by the processing means to a tray,
The control means includes
After the returning operation, the second transport unit discharges the sheet processed by the processing unit to the tray, and then causes the first transport unit to resume transport of the sheet.
A sheet processing apparatus. A sheet processing apparatus that can be attached to an image forming apparatus,
Processing means for processing the sheet;
Conveying means for conveying a sheet discharged from the image forming apparatus;
Instruction means for giving an instruction regarding a sheet discharge interval to the image forming apparatus based on information on a sheet processed by the processing means;
Execution means for causing the processing means to execute a return operation when it is determined that the processing means has reached an abnormal state during processing of the sheet;
A sheet processing apparatus. The sheet processing apparatus according to claim 4,
When the instruction means determines that there is a possibility of an abnormal state during processing of the sheet based on the information about the sheet, the instruction means discharges the sheet more than when it is determined that the possibility is not reached. Instructing the image forming apparatus to increase the interval;
A sheet processing apparatus. The sheet processing apparatus according to claim 4,
The instruction means includes
When the processing means determines that there is a possibility of an abnormal state during processing on the sheet based on the information about the sheet, at least the time required for the return operation than when it is determined that there is no possibility Only instructing the image forming apparatus to increase the sheet discharge interval.
A sheet processing apparatus. The sheet processing apparatus according to any one of claims 4 to 6,
The information regarding the sheet includes at least information regarding the type of the sheet,
A sheet processing apparatus. The sheet processing apparatus according to any one of claims 4 to 7,
Information about the sheet is received from the image forming apparatus;
A sheet processing apparatus. The sheet processing apparatus according to any one of claims 4 to 8,
Storage means for storing information associating information on the sheet with whether or not the processing means may reach an abnormal state during processing on the sheet;
A sheet processing apparatus. The sheet processing apparatus according to any one of claims 1 to 9,
The processing means includes
Staple means for binding a bundle of sheets,
Punching means for punching holes in the sheet, or
A binding means for binding and folding the sheet bundle,
A sheet processing apparatus. The sheet processing apparatus according to any one of claims 1 to 10,
The processing means includes
An operating part displaceable between a standby position positioned before processing and an operating position positioned during processing;
The return operation is an operation of positioning the operating unit at the standby position.
A sheet processing apparatus. An image forming apparatus;
Processing means for processing the sheet;
Conveying means for conveying a sheet discharged from the image forming apparatus to the processing means;
Control means for controlling the processing means and the conveying means,
The control means includes
When it is determined that the processing unit has reached an abnormal state during processing of the sheet, the conveyance unit stops conveyance of the sheet, causes the processing unit to perform a return operation, and after the return operation, the conveyance unit causes the sheet to Resume transport,
An image forming system. An image forming apparatus;
Processing means for processing the sheet;
Conveying means for conveying a sheet discharged from the image forming apparatus to the processing means;
Instruction means for giving an instruction regarding a sheet discharge interval to the image forming apparatus based on information on a sheet processed by the processing means;
Execution means for causing the processing means to execute a return operation when it is determined that the processing means has reached an abnormal state during processing of the sheet;
An image forming system. A control method for a sheet processing apparatus that can be attached to an image forming apparatus,
The sheet processing apparatus includes:
Processing means for processing the sheet;
Conveying means for conveying the sheet discharged from the image forming apparatus,
The control method is:
Determining whether the processing means has reached an abnormal state during processing on the sheet;
When it is determined that the abnormal state has been reached, the conveying unit stops conveying the sheet, and the processing unit performs a return operation;
A step of causing the conveying means to resume conveyance of the sheet after the returning operation,
A control method characterized by that. An image forming apparatus;
Processing means for processing the sheet;
A control unit for controlling the image forming system, comprising: a transport unit configured to transport a sheet discharged from the image forming apparatus to the processing unit;
A step of giving an instruction regarding a sheet discharge interval in the image forming apparatus based on information on a sheet processed by the processing unit;
A step of causing the processing means to perform a return operation when it is determined that the processing means has reached an abnormal state during processing on the sheet,
A control method characterized by that.